This proposed study is designed to investigate the acceptability, perceived need and uptake of short-term episodic Pre-Exposure Prophylaxis for HIV prevention among men who have sex with men (MSM). Long-term PrEP may be unnecessary for the many HIV-uninfected men who have episodic contextually defined high-risk periods, particularly when away from their home setting. Alternative dosing strategies, such as short-term fixed-interval episodic PrEP (Epi-PrEP), may be a more realistic, feasible, acceptable, and useful option with high public health impact for the majority of MSM. PrEP has the potential to dramatically raise the effectiveness of current HIV prevention efforts if it is correctly used and disseminated. This application is designed to investigate several questions essential to the development of efficacious Epi-PrEP uptake and adherence programs. The specific aims of the proposed two-city (Pittsburgh and Boston) study are to: (1) characterize and assess the prevalence of MSM who have high-risk but short-term periods when episodic PrEP may be an optimal HIV prevention strategy with a particular focus on low SES men; (2) determine the feasibility of clinic- based Epi-PrEP implementation pilot project for MSM who report occasional unprotected sex and who anticipate that they will have at defined high-risk time during the study period; and (3) Identify specific adherence-related contexts and problems, as well as resiliencies that will inform the intervention design of a larger scale trial of the effcacy of Epi-PrEP. Findings from this study will provide the empirical platform necessary to supporting the design, implementation and evaluation of an Epi-PrEP adherence intervention in a larger scale effectiveness trial. By basing the creation of new intervention strategies on data that measure both uptake and adherence of Epi-PrEP use among high-risk MSM, we can help ensure that PrEP strategies will reduce HIV transmission among the risk group that accounts for nearly two-thirds of all new HIV infections in the U.S.